This provision dates back to 1907, in connection with the adaptation to maritime warfare of the principles contained in the Geneva Convention of 1906. It was developed further in 1949, because of the clarifications added to the text of the First Convention.

[p.190] PARAGRAPH 1. -- REASONS AND CONDITIONS RELATING TO THE LOSS OF PROTECTION

The present paragraph is identical to Article 21 of the First Convention of 1949 . We shall examine the two sentences which it contains.

A. ' Acts harmful to the enemy. ' --The protection to which hospital ships and sick-bays are entitled cannot cease unless they are used to commit acts harmful to the enemy. The wording adopted by the 1949 Diplomatic Conference -- i.e., the negative form -- was intended to make it clear that protection could cease only in the one case mentioned, whereas in 1907 it had merely been stated that protection would cease if such acts were committed. Was the omission of any reference in this provision to coastal rescue craft deliberate, despite the fact that they are considered together with hospital ships in Articles 30 , 31 and 32 ? The documentation available does not provide an answer to the question. If rescue craft commit acts harmful to the enemy, then they will certainly be deprived of protection, in accordance with the general principles of the Convention and with Article 30 in particular. But it is less certain, in the absence of any reference to them in the present paragraph, that they can claim entitlement to the procedures mentioned in the second sentence, regarding due warning and a reasonable time-limit. For reasons of military security, it might have been difficult to extend those procedures to them, precisely because they are small and may be very rapid. In 1949 as in 1929, and as in the case of the First Convention, it was considered unnecessary to define "acts harmful to the enemy", for the meaning of the expression is self-evident and must remain quite general. While the International Committee of the Red Cross shared that view, it had prepared an alternative wording expressing the same idea in case the Conference should wish to be more explicit. We quote it here, as it may throw light on the meaning to be attached to the words "acts harmful to the enemy". It read as [p.191] follows: "acts the purpose or effect of which is to harm the adverse Party, by facilitating or impeding military operations". Such harmful acts would, for example, include carrying combatants or arms, transmitting military information by radio, or deliberately providing cover for a warship (1). The sense will become still clearer when we consider Article 35 , which quotes a series of conditions not to be regarded as harmful to the enemy. One thing is certain. Hospital ships must observe towards the opposing belligerent the neutrality which they claim for themselves and which is their right under the Convention. Being placed outside the struggle, they must loyally refrain from all interference, direct or indirect, in military operations. When committed by a hospital ship, an act harmful to the enemy is to be condemned not only for its treacherous nature, but also because the life and security of the wounded may be very seriously affected by its consequences. The text states specifically that protection may cease only in the case of harmful acts committed by hospital ships and sickbays "outside their humanitarian duties". It is indeed possible, as was stated at the 1949 Diplomatic Conference, for a humane duty to involve some harm to the enemy, or for it to be wrongly interpreted as harmful by an enemy lacking in generosity. But although the provision is justified in the First Convention, it is not so important in the present instance because of Article 30, paragraph 3 , which stipulates that hospital ships may in no wise hamper the movements of the combatants.

B. ' Warning and time-limit. ' -- The corresponding Article of the 1907 Convention merely provided that the protection to which hospital ships and sick-bays were entitled would cease if use were made of them to commit acts harmful to the enemy. The 1949 Conference added a further sentence with the object of tempering the possible consequences of too strict an application of the above principle. Safeguards had, in fact, to be provided in order to ensure the humane treatment of the wounded themselves, who could not be held responsible for any unlawful acts committed. [p.192] It is thus stipulated that protection may cease only after due warning has been given, naming in all appropriate cases a reasonable time-limit, and after such warning has remained unheeded. The enemy has therefore to warn the hospital ship to put an end to the harmful acts and must fix a time-limit on the expiry of which he may proceed to capture the vessel or even attack it if the warning has not been heeded. The period of respite is not specified. All that is said is that it must be reasonable. How is it to be determined? It will obviously vary according to the particular case, but must be long enough to enable the ship to stop the unlawful acts or to reply to an unfounded accusation and clear itself. The main purpose of the time-limit is undoubtedly to delay any attack on a hospital ship, for seizure would not involve comparable risks for the wounded. As we have seen, a time-limit is to be named "in all appropriate cases". There might obviously be cases where no time-limit could be allowed. Suppose, for example, that the crew of a hospital ship were to fire on a warship approaching it in order to search it. Fire would be returned immediately. Similarly, if the search revealed that the hospital ship was carrying not wounded persons but munitions, then it could be seized and the flagrant nature of the offence would justify the suppression of any time-limit. In any case of doubt as to the interpretation of the present provision, one must bear in mind that it is based on humanitarian considerations. As far as possible, a belligerent which deprives a hospital ship of protection because it has been guilty of a violation of the rules must take appropriate measures for the safety of the wounded on board before taking any extreme action.

PARAGRAPH 2. -- PROHIBITION OF SECRET CODE

This provision is new and was proposed by the experts who met in 1937 and subsequently in 1946 and 1947. Under Article 35, sub-paragraph (2) , hospital ships are authorized to carry radiotelegraph apparatus, but it was only after some hesitation that that clause was adopted in 1907. [p.193] The present paragraph is therefore an amendment to the earlier provision. The fact that the use of any secret code is prohibited affords a guarantee to the belligerents that hospital ships will not make improper use of their transmitting apparatus or any other means of communication. Hospital ships may only communicate in clear, or at least in a code which is universally known, and rightly so, for the spirit of the Geneva Conventions requires that there should be nothing secret in their behaviour vis-à-vis the enemy.

* (1) [(1) p.191] For the last instance, see the commentary on Article 30, p. 179 above;